I always use it quoting Pseudolus: “I’ll be back in a nonce. At most two nonces,”
I know “nonce” in the US sense. I was alerted to the UK sense in Spelling Bee discussions.
Ooh, good one!
I heard the derivation that its short for “nonsense crime” and it came from British prisons and originally meant any crime that didn’t make sense, e.g. random violence, crimes against children, etc. as opposed to regular crimes like burglary, assault, etc. that do “make sense”. But came to mean specifically pedophiles.
No idea if that’s the actual origin, I have no cites.
Wow, as an American I had no idea there were any slang meanings – I know it only as a very, very old-fashioned word for “occasion,” mostly used in the phrase “for the nonce,” or sometimes “nonce word.”
My other association with the word is that medieval and early modern writers tend to use “for the nonce” as generic filler, the same way we might use “you know.” Thus, Chaucer tells us that the Miller “was a stout carl [a strong churl] for the nones,” even though one assumes that he was a big, strong guy on all other occasions as well, and didn’t just bulk up to go on pilgrimage 
The OED does list its “sexual deviant” meaning, and says this about the etymology:
Origin unknown. Perhaps related to nance n., or perhaps compare English regional nonse good-for-nothing fellow, recorded in Eng. Dial. Dict. Suppl. from Lincolnshire.
Same here.
That was my first exposure to “nonce” and I used to use it all the time. I later heard it in the context of “nonce word” and never saw any connection.
I’d never heard it used as a synonym for pedophile, although I knew “nancy” or “nancy-boy” as an insulting term for homosexual, without any specific implication of pedophilia.
Huh, learned something today. I’ve only ever seen it in professional contexts of the cryptographic sense. I assumed it was some sort of portmanteau (if that’s the correct term in this instance) of “N” and “once”. Where N is commonly used to substitute for an arbitrary number in computer science (e.g. this loop needs to run N+1 times where N is the size of the list we pass to it), and once meaning, well, a single time.
So, N + once = Nonce. An arbitrary number we are only using a single time 
edit: and reading that Wikipedia page on cryptographic nonces - it would appear I’m not the only one who made this false assumption
I’m an American who’s watched a lot of British and Australian media. I only knew it as either a simpleton or what prisons over here would call a chomo.
A word I’ve never heard. Urban Dictionary says it’s a formation from “Child Molester”.
Just to be clear, the modern word meaning “sexual predator” and the older word meaning “for the current time” and similar senses are completely unrelated words which just happen to have the same form, like “bow” (bend forward) and “bow” (front of a ship). The older word “nonce”, according to the OED, does not derive directly from the word “once” but derives from an Old English word “anes” which means “at one time”, used in opposition to “twice”.
We clearly run in different crowds. More than a few of my friends and acquaintances over the years have been to prison, for drugs not the other thing. I’ve heard their stories.
Yeah, no ex-cons in my crowd. Yours are probably more fun.
I also don’t watch crime drama. We just had somebody casually toss out “DB” in a post about the Appalachian Trail and Appalachian dialect. They knew they meant “dead body” because they’re steeped in that television genre. Not I, and not the person who asked them for clarification.
Same but I also heard the cryptographic usage also.
Never heard of the pedophile meaning before this thread.
Specifically, child molester, but can be used for sex offenders more generally.
“Nonce” means “once” in that context (like nuncle = uncle…). I am not sure if that is supposed to be the same word as for stupid idiots and child molesters or just a homograph.
Yep, this was the standard word used for pedophiles/child molesters among my cohort during the late 90s/early 00s.
That’s the only way I’ve ever heard it used, and is what I immediately thought of when I read the thread title.